I recently asked the same question of her majesty’s revenue & customs and got the following reply:
In general, income arising from sources within the UK to a non-resident individual remains liable to UK tax.
Rents paid to a landlord whose usual place of abode is abroad must generally be paid under deduction of tax, at the basic rate (currently 22%). The landlord can however apply to receive the rents gross, and would then settle any liability directly with the Revenue, via Self Assessment. Booklet IR140 () and form NRL1 () refer.
Expenses incurred wholly and exclusively in the letting business will be allowable against rents received whether they are incurred in the UK or abroad. For further guidance on this subject please refer to H M Revenue & Customs Property Income Manual at
http://www.hmrc.gov.uk/manuals/pimmanual/index.htm, and in particular the instructions at PIM2100+.
TRADING ASSETS
If the asset to be disposed of is held in connection with a business or trade carried out in the UK, then any gain would be chargeable whether you are resident here or not.
It is unusual for a rental business to amount to a trade, but it can do, as in hotel and guest house businesses, for example. See our online Property Income Manual paragraph PIM4300 at
http://www.hmrc.gov.uk/manuals/pimmanual/PIM4300.htm
PERSONAL ASSETS
If the disposal is made in the non-resident period of the year of departure from the UK, it will give rise to a potential charge to Capital Gains Tax for the year of assessment.
If you left the UK before 17 March 1998 and the disposal is made during a year throughout which you are treated as not resident and not ordinarily resident, there will be no liability to UK Capital Gains Tax. But, if the disposal is made during the non-resident period of the year of return to the UK and the period of non-residence does not amount to at least five full tax years, there will be a potential charge to Capital Gains Tax for that year.
If you left the UK on or after 17 March 1998 and the disposal is made during a year throughout which you are treated as not resident and not ordinarily resident or, during the non-resident period of the year of return to the UK and, the period of non-residence does not cover at least five full tax years, this will also give rise to a potential charge to Capital Gains Tax. Gains for any of these years are aggregated and charged for the year of arrival, with only one annual CGT exemption.
Otherwise, the disposal by an individual not resident and not ordinarily resident will not be liable to Capital Gains Tax in the UK.
Further information about liability to Capital Gains Tax and temporary absences from the UK can be found in Self-Assessment helpsheet IR278 - 2004-05 version is at
and chapter 8 of booklet IR20 at
CALCULATION
If a charge to Capital Gains Tax does arise, the gain will be treated as the top slice of your income and charged at tax rates of, 10%, 20% and 40%. The annual exemption applicable to the year in which the gain is assessable will apply (£8,500 for 2005-06).
Working out the amount chargeable to CGT and how much tax you have to pay, is covered in Sections 9 and 10 of booklet CGT1 at
I am unable to comment on any liability you may have to tax in Ireland. That is a matter you will need to pursue with the relevant Irish authorities.